Keyboards, originally designed for typewriters, have long been a primary mechanism for receiving input from users of computers and other electronic devices. Originally, computer keyboards were predominantly mechanical devices that included arrays of physical keys that were triggered when depressed by users. A separate display such as a CRT monitor or LCD panel displayed information to the user, and the depression of keys resulted in the display of corresponding text characters on the display. Eventually computer keyboards were supplemented by pointing devices such as mice and track pads that controlled a movable pointer, enabling a user to “point and click” on graphical controls displayed on a display in order to perform desired operations on a computer.
More recently, however, touch screen displays have been developed, often eliminating the need for a separate physical keyboard and pointing device altogether. Touch screen displays, in particular, are finding uses in portable applications such as laptop computers, tablet computers, smartphones, and other mobile devices. Touch screen displays have the advantage of being highly intuitive as they enable a user to select operations simply by touching within an “active region” assigned to a displayed control (typically, a region that is closely aligned, if not identical, to the outer boundary of a displayed control).
Even as physical keyboards have been supplemented or supplanted by pointing devices and touch screen displays for much of the interaction between a user and a computer, keyboards remain popular because they are often the most efficient device for inputting textual information. As a result, even in portable electronic devices lacking physical keyboards, virtual keyboards are often displayed on touch screen displays to mimic the functionality of physical keyboards.
Virtual keyboards, however, are necessarily limited by the lack of a physical interaction between a user's fingers and the keys of a physical keyboard. Keys in a physical keyboard are typically raised from the surface of the keyboard housing, and may be indented and/or provided with protrusions so that a user can often subconsciously rely on their sense of touch to efficiently move their fingers to desired keys on the keyboard. Keyboards displayed on a touch screen display, in contrast, are displayed on a flat surface, and a user therefore cannot rely on their sense of touch to navigate their fingers between keys. As a result, virtual keyboards are typically subject to more erroneous inputs, often necessitating that a user either backup and re-type erroneous characters on a more frequent basis, or rely more on their sense of sight to ensure they touch in the proper locations on the display, both of which slow down user input and lead to less efficient user interaction.
Significant research has been focused on improving the ergonomics of physical keyboards, primarily due to overuse injuries such as carpal tunnel syndrome. The typewriter keyboard layout that is the de facto standard for most electronic devices, referred to as the QWERTY keyboard based upon the locations of the Q, W, E, R, T and Y keys at the top left of the keyboard, was originally developed to slow down typists who were able to type faster than early mechanical typewriters could handle, and ironically, much of the research subsequent to the adoption of QWERTY keyboards has been directed toward making QWERTY keyboards more efficient and comfortable for users. For example, ergonomic keyboard designs have been developed that separate the left and right halves of a keyboard and reorient them to place a user's wrists in a more natural orientation while typing. However, given that every user will have slightly different physiological characteristics, e.g., different finger and hand sizes and biomechanics, it remains difficult to design a keyboard that is optimally configured for all possible users.
Likewise, for touch screen keyboards, some efforts have been directed toward keyboard layouts that increase user comfort, efficiency and accuracy. For example, similar to some ergonomic physical keyboards, virtual keyboards have been developed with separate left and right groupings of keys. Furthermore, some virtual keyboards have been developed that permit groups of keys to be moved, resized and rotated by a user to position the keys in a comfortable location and orientation for a particular user.
In addition, some development efforts have been directed towards tracking user interaction with a virtual keyboard and adjusting the positions of keys based upon the user's interaction with the keyboard. The actual locations touched by users can be monitored and used to repositions of keys so that, for example, if a user consistently touches the A key in an upper left corner of the active region of the key, the key can be moved up and to the left so that the user's future touches will land closer to the center of the key, thereby minimizing the likelihood that the user misses the key in the future.
Despite these improvements, however, a substantial need continues to exist for a manner of improving the efficiency, comfort and accuracy of touch screen keyboards.